1. Field of The Invention
The present invention relates to an image recording apparatus, e.g., a color scanner, for recording an image to be reproduced onto a photosensitive material. In an image recording apparatus according to the present invention, a photosensitive material is pulled out of a roll containing the same and fed in the feeding direction while scanned with a laser beam which sweeps in a direction approximately perpendicular to the feeding direction of the photosensitive material. The present invention also relates to a method of recording an image.
2. Description of The Prior Art
In such an image recording apparatus as above to which the present invention is directed, the following is a common practice: A photosensitive material pulled out of a film case is fed in a feed scanning direction by rotation of a main roller while firmly holding the photosensitive material between the main roller and nip rollers. The image recording apparatus comprises an expose-scanning unit for sweeping a laser beam in a primary scanning direction synchronously with feed of The photosensitive material in the feed scanning direction, whereby an image to be reproduced is recorded on the photosensitive material. The photosensitive material with an exposed portion is further fed by a predetermined length in the feed scanning direction, to be automatically cut off by a cutter unit disposed in the image recording apparatus. Thus, a predetermined-size sheet with the image reproduced thereon is produced.
A general knowledge in the art is that it is highly required to attain not only stable but also smooth feed in feeding a photosensitive material in the feed scanning direction in order to assure the reproduced image of excellent quality. Unfortunately, a conventional apparatus has a weakness in this regard. As mentioned above, a photosensitive material is drawn out of the film case by rotation of the main roller to be fed. At the same time, the photosensitive material is kept firmly held between a pair of introduction rollers. This would cause tension to act upon the photosensitive material, which is now on the main roller, in the opposite direction to the feed scanning direction. Such tension would in turn cause the photosensitive material to slip between the main roller and the nip rollers. And this would then follow, if not always, that the photosensitive material is fed with unstable feed. In addition, force requisite for pulling out the photosensitive material from the roll thereof varies depending on amount of the photosensitive material remaining in the roll. Hence, amount of remaining photosensitive material in the roll is considered to exert significant influence on feed of the photosensitive material.
Various techniques have been established which solve such problems. Among those is the technique disclosed in Japanese Laid-Open Gazette No. 63-71061.
FIG. 1 is a sectional view of an image recording apparatus disclosed in the gazette No. 63-71061. In FIG. 1, introduction rollers 101, holding a leading edge portion of a photosensitive material roll 105, rotates to draw a photosensitive material 103 out of the roll 105 into a contacting area between a main roller 102 and nip rollers 106. The main roller 102 then rotates while firmly holding the photosensitive material 103 in its contacting area with the nip rollers 106, consequently feeding in a feed scanning direction the photosensitive material 103 on which a laser beam 104 runs in a primary scanning direction concurrently with the feed. As a result of this, an image to be reproduced can be recorded on the photosensitive material 103. In the image recording apparatus, a portion of the photosensitive material 103 is loosened between the introduction rollers 101 and the main roller 102 by a predetermined length, and the leading edge portion 102a, which has exposed, is let down. This allows an image to be recorded onto the photosensitive material 103 while preventing the same from slipping on the main roller 102.
After recording of the image, the main roller 102 reversely rotates to wind the photosensitive material 103. Then, the main roller 102 rotates again in its normal direction, to thereby send the photosensitive material 103 by a predetermined distance toward a cutter 107 and guide rolls 108, where the photosensitive material 103 would be cut off. Thus, a photosensitive material sheet of a predetermined length is produced, the sheet having the reproduced image.
The image recording apparatus as above secures continuous recording of the image by rewinding the photosensitive material which has an exposed portion; however, the rewinding is a source of problem. Until a film case 105a will be replaced by a new one, a "set condition" must be maintained wherein the main roller 102 and the nip rollers 106 are in contact with each other. During the set condition, a production cycle described above; precisely, a set of procedures consists of exposure, rewind, normal feed and cut is repeatedly performed in this order. As the repetition of the production cycle increases in number, the set condition gradually deviates from its original state. That is, variation occurs in a size of a loosening which is formed between the main roller 102 and the nip rollers 106.
A possible solution of this is to reset the apparatus to initial state after rewinding a photosensitive material for every production cycle. More precisely, a photosensitive material with an unexposed portion is rewound, for every exposure, so that the leading edge portion thereof retreats to the position of the introduction rollers 101. The image recording apparatus is thus reset to the initial state for every rewind. Consequently, a loosening between the main roller 102 and the nip rollers 106 can be maintained in a predetermined size.
However, this solution invites a deteriorating effect. Time required for producing one photosensitive material sheet, that is, a cycle time becomes long. This would in turn result in a decelerated production efficiency.